Keith Olbermann’s big head is about to explode. Next on Countdown.

Gawker reports rumblings of a potential snit at MSNBC, aka Fox News/Left Division, between the shrill and rant-prone Keith Olbermann and perky Rachel Maddow, the Miss Congeniality of leftist punditry.

At the heart of the matter is Ben Affleck, whose dead-on parody of Olbermann on Saturday Night Live four days before the November elections was one of the classic and most brutal beatings ever delivered in the annals of mimicry, celebrity or otherwise.

Piecing the story together from several sources, Gawker learns that Maddow booked Affleck on her show. Olbermann, behind the scenes, wasn’t happy because he wanted the booking, ostensibly so he could bask in the glow of the attention from being such a good sport.

What followed next is childish … and predictable. Olbermann took some time off, according the City Files site, claiming he had sad issues to deal with following the death of his mother two weeks ago. Then came the tweet of his MSNBC colleague David Shuster, which explained that Olbermann was suffering from allergies. And then Gawker dug up this picture…